Chapter 4.6, Problem 4.56P

Interpretation Introduction

Interpretation:

Directing effects of the given compound have to be predicted.

Concept Introduction:

Deactivators are electron withdrawing groups attached to the benzenes that have either positive charge or an atom with high electronegativity. They are meta directors.

• Strong deactivators: They are very strong electron withdrawing groups.
• Moderate deactivators: It contains a pi bond that is attached to a strong electronegative group.
• Weak deactivators: It consists of halogens.

Activators are electron donating groups attached to the benzenes that have either electron density that is able to push into benzene ring or a lone pair of electrons. They are ortho-para directing.

• Strong activators: It contains a lone pair next to the aromatic ring.
• Moderate activators: It has a lone pair next to the aromatic ring that can take part in the resonance outside the ring as well.
• Weak activators: It consists of alkyl groups.

Halogens are deactivators that are ortho-para directing.

Rules to identify the group that dominates the directing effects:

• Ortho-para directors will always dominate meta directors.
• Strong activators will always dominate weak activators.